A simple and reliable method for determination of skin perfusion pressure in patients with severe occlusive arterial disease.
In an attempt to simplify the pre-operative assessment of amputation level in patients with severe occlusive arterial disease of the legs the skin perfusion pressure (SPPp) on calf and/or thigh was determined photo-electrically in 38 patients, aged 41-85 years and compared to the pressure values (SPPi) determined by the widely used but cumbersome isotope washout technique. SPPi was determined as the minimal external counter pressure (applied by a blood cuff) sufficient to stop the washout from an intracutaneous depot of Na131I- mixed with histamine. SPPp was determined as the minimal external counter pressure required to prevent skin reddening after blanching of the skin. The systolic blood pressure, determined indirectly by strain gauge technique at the same level of the leg, was used for reading the SPPp as that counter pressure at which the photo-electric tracing moves away from a straight line placed on the tracing through the counter pressure corresponding to the systolic blood pressure. In the studied range 18-88 mmHg there was no significant difference between SPPp and SPPi. The total day-to-day variation of SPPp, determined from ten double determinations in eight patients was 6.6 mmHg (range of SPPp:23-80 mmHg). The present results indicate that assessment of amputation level from SPPp using the standardized reading should offer a reliable alternative to the isotope washout method. The photo-electric technique is simple and fast, and gives only negligible discomfort to the patient.